成都市妇保医院做孕检多少钱
时间:2019年06月21日 00:20:22

Out for the Count失去知觉之后If youve ever had major surgery, you probably remember lying down and waking up—but nothing in between. Thanks to the anesthesiologist, during the actual surgery you were out of it: immobilized and insensitive to pain. But until recently scientists had little understanding of how anesthetics actually work on the cellular level.如果你曾经做过重大手术,那么你肯定只记得躺下去和醒来这么2个动作,而其间过程是浑然不知的。多亏了麻醉师,你才能在手术中无知觉地度过:不能动弹,也感觉不到疼痛。但是直到最近科学家们才多少了解到麻醉药是如何在细胞层面上工作的。Thats changed thanks to recent experiments performed by researchers at the University of Zurich, in Switzerland. They knew that anesthetics caused pain receptors in the brain to turn off by acting like most drugs do: anesthetizing drugs attach to particular sites on nerve cells and turn them off. The question was, where on nerve cells do these drugs attach?还得感谢瑞士苏黎世大学的研究员们最近做的实验,这一困惑才得以解开。他们弄清楚了麻药是通 过关闭大脑中的疼痛接收器才使人感觉不到疼痛,原理跟大多数药物一样:麻药附着在神经细胞上某个特殊位置,然后将感知功能关闭。问题是,麻药到底附着在什么位置呢?Nerve cell membranes have receptors for different kinds of chemicals produced by the brain. Gamma-amino butyric acid, or GABA, for example, is a chemical that shuts down nerve cells. The hypothesis was that general anesthesia works by binding to GABA receptors on a nerve cell, thereby activating the receptor and instructing the cell to shut down. So it made sense for the Zurich researchers to focus on GABA receptors.神经细胞膜有多个接收器来识别大脑产生的不同类别的化学物质。例如γ-氨基丁酸,或者简写为GABA,就是可以关闭神经细胞感知功能的化学物质。假设全身麻醉是将麻药和在神经细胞上的GABA接收器绑定在一起,从而激活接收器,然后再传达闭接收功能的指令关的。这样的假设就使苏黎世大学的研究员们明白,集中精力研究GABA接收器是关键所在。To do this they worked with mice that had been genetically engineered to have nerve cells with GABA receptors that wouldnt respond to anesthetics. And sure enough, when such mice were given anesthetic drugs they werent nearly as immune to pain as regular mice that had also been given pain-blocking drugs. Clearly, GABA receptor sites on nerve cells are part of what allows anesthetics to do their job.为了明这点,他们用基因改造过的老鼠做实验,这种老鼠身上的 GABA接收器对麻药免疫。毫无疑问,这样的老鼠在使用了麻药后,比起正常的用了麻药的老鼠,疼痛感几乎没有降低。显然位于神经细胞上的GABA接收器是让麻药起作用的原因之一。While the Zurich experiment fills in only one piece of the puzzle, it is an important step towards learning how these amazing drugs work, and how to make them even better.尽管苏黎世大学做的实验只解决了一小部分困惑,但是这对于了解这些神奇的药物如何工作的,以及怎样让它们发挥更好的效果是重要的一步。 /201208/193298

Books and Arts; Book Review;A history of dieting;Binge and purge;文艺;书评;节食的历史;狂欢和清理;Calories and Corsets: A History of Dieting Over 2000 Years. By Louise Foxcroft.《卡路里和束身衣:2000年来的节食历史》 Lousise Foxcroft 著。After the binge of the holidays, many stumble into January with a hangover, some fragile resolutions and a desire to shed a few pounds. Alas, few will benefit from rigid calorie-counting or cabbage-soup slurping. In a recent study of 31 long-term diet plans, the American Psychological Association found that up to two-thirds of participants ended up heavier than before they started. Some diets are more sensible than others, but any regimen that promises swift and dramatic results will doom most followers to failure. Weight-loss pills and surgery are similarly ineffective—and sometimes dangerous—over time. Yet girth-management is big business, full of charismatic hucksters and fake science (fat-burning lip balm?), earning billion a year in America alone.在假日的狂欢之后,许多人宿醉,下着不坚定的决心,立志要减去数磅体重,在跌跌撞撞中进入了一月。哎呀,少有人会得益于严格计算卡路里饮食或是食用卷心菜汤所带来的好处。最近有一项关于31个长期节食计划的研究,美国心理协会发现有超过三分之二的参与者在结束计划时比他们开始时还要重。一些饮食计划明显比其他的要有效果,但是任何承诺快速有效的养生方法都注定让它的实践者们失败。减肥药片和手术经过时间的验,同样效果不佳——有时甚至很危险。然而,腰围管理仍然是一件大事,这里充满着有推销能力的商家和伪科学(燃烧脂肪的唇膏?),每年就仅仅在美国就可以挣得400亿美元。“The diet industry is all about exploitation and profit,” writes Louise Foxcroft in “Calories and Corsets”, her slim new book about the history of dieting. Less a banquet than a tasting (the tone is breezy, opinionated and occasionally rushed), she chronicles more than 2,000 years of movers, shakers and tummy-tuckers, highlighting both the wise and the wacky.“节食产业几乎只有开发和盈利” Louise Foxcroft在《卡路里和束束身衣》一书中写道,她薄薄的新书描述了节食的历史。她的书与其说是一场盛宴,不如说是一本激起人食欲的菜单(整本书语调轻松,观点明确,有时有些咄咄逼人),Foxcroft按时间顺序,编写了2000多年来的行动者, 有影响的人物和减肥人士, 既写聪明人,也记叙古怪的人。The word diet comes from the Greek diaita, an approach to health that linked the mental with the physical. Classical physicians saw being too fat or thin as a sign of an imbalance. Man “cannot live healthily on food without a certain amount of exercise”, observed Hippocrates, who believed in breakfast, long walks and prudent vomiting. Philosophers such as Socrates saw a relationship between food and ethics, as a taste for luxury often leads to greed and unjust behaviour.“diet”节食这个单词来源于希腊语“diata”,意思是使身体和心灵都健康的方法。传统的医师认为太胖或者太瘦都是不平衡的标志。人类“依靠食物健康地生存必须要有定量的运动” 希波克拉底得出这个结论,他崇尚早餐,长距离的行走和适当呕吐。哲学家如苏格拉底发现了食物和道德之间的关系,吃大餐通常会导致人的贪婪和不公平行为。Unlike the other deadly sins, gluttony is visible and so is often judged harshly, as if heft were always evidence of wanton indulgence or laziness. (The link between genetics and metabolism was not discovered until the 20th century.) In particularly hard times such as the two world wars, fat people were seen as traitors. Greater access to food and a rising stigma against podge helped inspire the fashion for corsets in the 17th century, which caused overlapping ribs, bad breath and the occasional death. When it comes to diets, women occupy a perversely central place, argues Ms Foxcroft. They are condemned for their gluttony, criticised for their vanity, manipulated for their insecurity心神不定 and also blamed for the flab on their husbands and children.不同于其他致命的罪恶,暴饮暴食是显而易见的,因此常招致严厉的批评,似乎重量就是放肆纵容和懒惰的据(直到20世纪,遗传学和新陈代谢之间的联系才被发现)尤其是在艰难时期如两次世界大战,肥胖的人往往被视为是叛徒。17世纪,人们可以吃到更多的食物,对于矮胖之人的羞辱也与日俱增,这一切引发了束身衣的流行。束身衣可以致使人肋骨重叠,口臭,甚至是死亡。Foxcroft 女士指出,当谈到节食时,女性通常占据着主导地位。她们常因暴食受到谴责,因虚荣招致批评,因心神不定而被人利用,因丈夫和孩子身上的肥肉受到指责。Until the 18th century, ideas on diet were mostly about healthy eating, morality and control. Laxatives and emetics were common, but many philosophers and physicians had sensible ideas about restraint and nutrition. By the early 19th century complaints about fat became rife, as even the working class had moved from the fields to the calorie-rich cities. This created a larger market for dieting solutions, particularly fads such as cold-rain douches, chest beatings, electrode zappings and massages that promised to crush subcutaneous fat globules.直到18世纪,人们关于节食的想法大都关于健康饮食,道德和控制。排泄和催吐非常普遍,但是许多哲学家和医师对于抑制和营养有着明智的看法。到19世纪早期,当工人阶级从农村搬到充满卡路里的城市,人们对于肥胖的抱怨开始流行起来。这为节食计划创造了更大的市场,尤其是冷水灌洗,击打胸部,电极刺激和这些承诺可以减少皮下脂肪的方法。The 19th century saw a chap named William Banting bring the first low-carbohydrate diet to a mass audience. A study in the Lancet later confirmed the value of favouring protein and fat over carbs well before a once overweight cardiologist named Robert Atkins figured this out for himself. Horace Fletcher, otherwise known as “The Great Masticator”, was emphatic about chewing each mouthful of food until it was liquid, and counted John D. Rockefeller and Franz Kafka among his disciples.在19世纪,有个叫做William Banting的人,他第一次将低碳水化合物食谱推荐给大众。后来在《柳叶刀》中刊登的一项研究实了多摄入蛋白质和脂肪,少摄入碳水化合物的好处,在此之后,有一个曾经超重的心脏病专家Robert Atkins也为自己指出了这一点。Horace Fletcher,以“伟大的咀嚼者”广为所知,曾强调咀嚼每一口食物直到它们成了液体,他的拥趸包括洛克菲勒和卡夫卡。There have been other gurus, plans, drugs and devices, but most offer short-lived results and long-term angst. Lasting changes need slow but steady modifications to lifestyle. Inspired by those early Greeks, who wished to achieve personal balance, not an ideal body type, Ms Foxcroft offers a suggestion that sounds enough like a resolution: “make sensible choices and stick to them.”还有些权威,节食计划,药品和设备,但是大多数方法都缩短了人的寿命,引起了人们长期的愤怒。持久的变化需要对生活方式进行缓慢但稳定的调整。Foxcroft女士受到了早期希腊人的启发,要想获得个人的平衡,而不是理想的身材。她出了一个建议,但听起来更像一个决心:做理智的选择,并且持之以恒。 /201211/210180

Frozen Smoke固体烟Male:Whats as light as smoke but strong as a brick?什么东西既可以跟烟一样轻,又可以跟砖块一样重?Female:Im gonna take a while guess and say... aerogel?让我想会儿……气凝胶?Male:Sorry,yaoyao,the answer is... Wait a second! Did you say aerogel? How did you know?瑶瑶,不好意思,是……等等!你说的是气凝胶吗?你是怎么知道的?F:Yeap! Did you know that aerogel is the lightest solid on earth?是的!你知道气凝胶是地球上最轻的固体吗?M:I was going to tell you that.我刚刚正要告诉你呢!F:Another cool thing is that it starts out as a kind of chemical Jello. Then the gel is dried in a powerful pressure cooker and emerges as a very lightweight, dry, sponge-like material that looks like frozen smoke.了不起的是,气凝胶开始是作为一种化学凝胶物的。然后胶体在压力很强的锅里变干,成为了一种重量很轻、很干燥、类似海绵状,看起来像固体烟雾的物体。M:OK! Did you know that aerogel is ninety-nine-point-eight percent air?是的!那你知道气凝胶中99.8%都是空气吗?F:Sure.That was in your notes.And its incredibly light-one thousand times less dense than glass. But its also really strong and an excellent insulator.知道啊!你的笔记中有的!气凝胶相当的轻,轻到密度只有玻璃的千分之一。但它也很结实,是几号的绝缘体。M:Is there anything you dont know about aerogel? For instance,scientists are using it to try to capture dust particles from the tail of a comet. When the particlesslam into an aerogelpanel aboard a space probe, theyll bury themselves inside and leave visible trails. Since aerogel is mostly air, it wont damage the particles.关于气凝胶,你还有什么不知道的吗?比如说,科学家正在试图用它捕捉彗星经过的微尘。当(微尘)颗粒猛烈撞击到航空探测器上的气凝胶板时,它们将会自然,从而留下可见的痕迹。因为气凝胶差不多等同于空气,并不会破坏(微尘)颗粒。F:Actually, I know that too.其实这个我也知道! /201208/197050


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